Plastic electronics keeps making progress. At EPFL researchers have created a conductor that can be stretched up to four times its length maintaining its conductivity.

This means that you can place this conductor on a sheet of plastic and it will work as the plastic sheet is bended and stretched (take a look at the video clip).

To get this result the researchers have developed conductive tracks with a thickness of a few hundredth nanometers on a film. The tracks are made of gallium with gold particles that is deposited in vapour form on the film. The deposition of gallium results in a sort of liquid track and it is this liquid form that enables the physical characteristics. The gold particles avoid the molecules of gallium to aggregate in droplets separating one from the other, thus leading to a break in conductivity. The resulting conductor is as bendable and as stretchable as the plastic film, surviving a million stretches.

It looks like the ideal material to serve as skin to robots, embedding sensors in it, as well as a band (with sensors) to be placed on our skin. It can bend and stretch in the same way our skin does, including the one in places as critical as a finger (look at what happen to your skin when you move a finger to grab something: it stretches and bends quite a lot!).